Former U.N. chief Kofi Annan warned late Wednesday of a "crisis of confidence" in Kenya's leadership and told the nation that it risks returning to violent ethnic clashes if key reforms are not quickly implemented. A recent report suggests that the next round of violence would not be fought chiefly with spears and machetes, but with firearms.

In his parting remarks after a three-day visit, Kofi Annan pushed Kenya's leaders to listen to the will of the people calling for change.

"My conversations with Kenyans during the last three days have underscored that there is a crisis of confidence in Kenya's political leadership," Annan said. "Only Kenya's politicians can solve that crisis. I urge them to listen to the voices of Kenyans."

Annan softened his criticism by saying that he had noted some progress on the reform agenda but warned that time was running out.

Politically-fueled ethnic tensions flared up in early 2008 following a disputed presidential election, plunging Kenya into weeks of deadly turmoil.

Flown in to mediate the crisis, Annan led the two sides to a power-sharing agreement that made incumbent candidate Mwai Kibaki president and his rival, Raila Odinga, prime minister. The deal brought an end to the clashes, but has resulted in a bloated coalition government unchallenged by a real political opposition.

As part of the agreement between the two principle rivals, the new government agreed to undergo a far-reaching reform agenda to prevent the tensions from boiling over in the next election. Critics claim that the government has not followed through on its commitments, an accusation the government strongly denies.

Annan said Wednesday that the nation "cannot afford another cycle of violence," warning that the government's term is already halfway expired and the 2012 elections are quickly approaching.

Overshadowing the former U.N. chief's remarks was a BBC report early Wednesday that claims ethnic groups in the regions most hit by the 2008 violence are now stockpiling guns to prepare for 2012.

The 2008 conflict, the nation's worst since its independence more than 45 years ago, was carried out chiefly by machete-wielding gangs in the slums and in the affected rural areas by tribal militias armed armed primarily with spears and bows and arrows.

Hassan Omar, vice chairman of the Kenyan National Commission on Human Rights, said that his group has also received reports about groups purchasing firearms but has as yet been unable to independently verify the claims.

"The allegations are becoming more and more credible," Omar said. "The Kenya National Commission [on Human Rights] did have these allegations, and we had not necessarily undertaken the time of investigation or documentation towards proving their existence."

According to the private fears expressed by a senior parliamentary official, another flare-up similar to the 2008 turmoil has the potential to fragment the nation into regional power-centers run by tribal warlords, given the country's current political climate and simmering ethnic tensions.

But Kenyan cabinet minister William Ruto, a political leader of one of the ethnic groups named by the BBC report for buying the guns, dismissed the claims as rumors.

"The people making these allegations should either come forward with substance to their claims, or they should shut up," Ruto said. "I don't think rumor mongering is going to take this country anywhere."

The United States has threatened 15 senior Kenyan officials with travel bans if the reform process is perceived as continuing to stall.